Frequency stabilizer



Jan. 2, 1940. R. ORTHUBER ET AL.l

FREQUENCY STABILIIZER Filed Feb. 26, 1937 I; y H 17-55 INVENTORS RICHARD ORTHUBER EBERHARD STEUDEL BY l 44m/JA,

ATTORN EY "Patented Jan. 2, 1ero?v y rist-,606

'fr-er' FREQUENCY sraBILIzER r Richard Ortlhuber and Eberhard Steudel, Berlin, Germany, assignors to Allgemeinel Elektricitats Gesellschaft, Berlin, Germany, a corporation ci y Germany v. ApplicationfFebruary 26, 1937, Serial No. 127,840

In Germany February 26, 1936 s claims. (orzsowgsa) lication disclosesan arrangement which serves for amplifying an electron current. This 'arrangement consists oi"l two electrodesarranged in a vacuum Vessel, and which havean-alternating potential impressedthereon' such that electrons emanating fromthe one electrode, are ac-` celerated towards the other .electrodejin thel one` phase'of the alternating potential, and' release ythereat secondary electrons which in turn are again accelerated back to the rst electrode in t'he second phase. 'a multiplication of the original electron current by secondary electrons. This secondary electronv multiplier just as the piezo-electric quarta has V a certain natural frequency,`at which its inner resistance i's-a purely ohmic resistance. In the general case the impedance of the multiplier depends on the frequency of the exciting potential,

and is apurely capacitive reactance especially at y low frequencies.

In accordance with the invention for stabilizing the frequency of an oscillatory circuit a socalled dynamicv type multiplier device of the character above suggested is utilized in place of a piezo-crystal. The dynamic type electron multiplier tube and circuit combination is suited for the frequency stabilization is .due to the fact that owing toits small damping rit was found that itv hasy a sharp resonancey curve similar to that of the piezo-quartz.

An `embodiment of the'y arrangement accordit will be appreciated that other types of oscillators may be used equally as well and while they ing to the inventionv is shown in the drawing by way of example. The ideacf the invention will lnow be elucidated by referencelto this drawing. In the known oscillatory circuit, comprising inductance 2 and capacity 3, an electronic dynamic type. multiplier "4 is inserted.. The multiplier tube has two electrodes cathodes) 5 which carry *ther alternatingppotential vto Abe maintained constant. The resonance frequency of 'thev multiplier f can be set at willby means ofthe direct potential appliedfto'a cylinder (the anode) 'B and the resonance resistance ofy the multiplierl can be varied Aby means of a magnetic'eld produced by a coil 'l arranged t'o surround the tube 4 for substantially its length, The coil 1 is energized from a potential source 8 'arranged'vin series with a current meter 9 to indicatel the current owing.

The ianode sgsupplied with `volta-ge from the In this way theretakesA place 'source ill which has one terminal connected to'.- the ycentral point of `the inductance i of the oscillatory circuit.'

The ends of the oscillatory circuit are connected' to the electrodes or cath:- odes t ci'4 the multipliertube il.

In the arrangement by which the invention has been illustrated fork convenience the system has vbeen shown in the form of a Hartley oscillatory circuit where the inductive element has been center-tapped and connected to the cathodev il4 of the` oscillator tube I2 through the battery it' eine* which is so poled that itsupplies positive Voltage to the. anode ill of this oscillator tube. In the :connection shown the anode it of the oscillator tube l2 connects to one end of the oscillatory or tank circuit and the grid electrode i5 con? vnects to vthe opposite end ci the oscillatoryor 1lii In this arrangement it will be seen that the @multiplier tube oinbination replaces the piezoelectric crystal which for a Hartley type oscillator` .I

is connected in one form across the oscillatory circuit. Of course,it will be apparent that the multiplier tube may also be connected in any other manner than that shown, as iswell known,

for establishing connections of the piezo-electric crystals'in order to stabilize any type of oscillator.` Furthermore, it will be apparent that while the invention has beenllustratedin connection with the form of Hartley type oscillator,

so-called shunt feed type of Hartley circuit is illustrated, it is, of course, obvious that the'in- Vention appliesequally well to vthe so-called series feed type device. .Y

Also it is apparent that the arrangement is' y equally adapted to use with the so-called Cclpitts type oscillator or withthe tune-plate-tune-grid electron multiplier device, with all of the 'foregoing types of oscillators, has not been specifically illustrated, it is of course, apparent-that thisy while f `r dynamic type 'multiplier device when used lwithr circuits of the foregoing types, would be connected in accordance with the manner shown `in the present invention and substituted for the crystal customarily used for stabilizing `the oscillator.

It will be appreciated that this form of oscillatory control offers a material advantage in many instances over the piezo-electric crystal type because of the fact that it is possible to derive high power at once, whereas in the piezo-fA 4electric type of control, heating of the crystal 4l.occurs upon a material increase in power with the result that a drift' in the oscillatory frequency rangement is especially suited for stabilizing short waves, which can only be accomplished with diculty when using a quartz crystal or other piezo-electric substances in View of the,

fact that it is technically dime-ult to obtain these substances with the small dimensions necessary for this purpose.

Eventually it will be necessary that by the use of electron optical reproduction elements the electrons are prevented from impinging on the plate cylinder 6, in order that the damping be as low as possible, and on the other hand, it will be suitable to take care that the electrons will only be multiplied to a minor degree so that a delivery of electrons to the plate cylinders will not be necessary.

We claim:

1. In combination, a thermionic oscillator in# cluding an oscillatory tank circuit, secondary emission means having a predetermined resonant operating frequency, and means for connecting said means in parallel with the oscillatory tank circuit for stabilizing the oscillator,

2. A thermionic oscillator comprising a .oscillatory tank circuit having a relatively broad operating range, means connected effectively in parallelwith the tank circuitvhaving a narrow resonant operating range comprising a pair of` opposed cathodes and. means for maintaining electron traversal `and retraversal in the space between the cathodesl at resonant `frequency for stabilizing the oscillator.

3. A thermionic oscillator including anposcilr.

latory tank circuit, means connected effectively. Y' 'in parallel with the tank circuit comprising a y pair of opposed cathodes-and means for maintaining resonant electronic oscillations between `the cathodes for stabilizing the rate'of operation of the oscillator at resonant frequency by elec- I' tronic oscillations between said cathodes.

4. Anoscillator comprising a thermionic tube i having a plurality of electrodes `and an oscillatory.v circuit, means for connecting certain of the elec` trodes to the oscillatory circuit, means to stabilize the rate of operation of the oscillator comprising l a pair of opposed plates connected eiectively in parallel with the oscillatory'circuit, and means',I including said piates, for producing and Aoscillat-l ing secondary electrons therebetween whereby the` rate oi operation of theoscillatorv is deter! mined by the resonant frequency of the 'secondary electron oscillator.

5. An oscillator comprising a thermionic tube having a plurality of electrodes .and an oscillatory. circuit, means for connecting the electrodes to the oscillatory circuit, means to stabilize'v the oscillator comprising a pair of opposed cathodes connected eiectively inparallel with the oscil-,i`

latory circuit, yeach having surfaces adapted to emit electrons by impact, and means to main-l tain electron oscillation between the cathodes Vat resonant frequency vwhereby theoscillating frequency of the oscillator is determinedl thereby.`

6. In combination, a thermionic oscillator comprising an oscillatory tank circuit and means-tof` stabilize the oscillator comprising a pair of op'-4 posed cathodesconnected 'to the ends of the tank i circuit, said cathodes being adapted to emit secondary electrons by impact,` an anode positioned between said cathodes, means for connecting said anode to the midpoint ofthe tank cir-` cuit, and means, including said cathodes. for

maintaining resonant electron oscillation between the cathodes. l f

- EBERHARDl STEUDEL.

RICHARD` ORTHUBER. 

